Hexokinase of the rumen microorganism Quins oval

Abstract

Quin (1943) first noted that the characteristic large gas production observed in sheep fed on high sugar diets of green lucerne, lucerne hay & molasses, was due in the main to the rumen microorganism – Quins Oval – which was found in large numbers in the rumen of such sheep. He observed rapid gas production with preparations of these organisms when they were incubated with glucose. McGaughey & Sellers (1948) also found that Quins Oval (QO) became predominant when sheep were fed hay supplemented with mangolds.

Recent studies by Wicken & Howard (1967) on the cell wall of this organism are consistent with classification of it as a Gram-negative bacterium. Fermentation studies by Brought.et.al (1970) have indicated that suspensions of QO fermented glucose, fructose & sucrose rapidly, mannitol moderately quickly, maltose slowly, but had no action on a number of other mono- & oligo-saccharides & starch. The present work was undertaken to determine whether there were kinases present in cell-free extracts of QO capable of phosphorylating certain monosaccharides that had been shown to have been fermented by this organism. Further work involved purification of a hexokinase from QO & comparison of the properties of this enzyme with those of hexokinases from other organisms.